Synthetic studies toward frutescone O and Menaquinol-7

초록

Frutescone natural products has been isolated from eastern Asian herb Baeckea frutescens. Recently, frutescone H-R was isolated along with the potent anti-inflammatory activity. Frutescone O possess most promising activity but it has never been synthesized yet. Synthetic study for this natural product will lead us to a new class of anti-inflammatory drug candidates. Frutescone O has tetracyclic structure including a spirocarbon and a cyclopropane. Proposed biosynthetic pathway suggest that the tasmanone derivative and the sabina ketone derivative would be a good candidates of the key fragments for the total synthesis. To achieve the fragment syntheses, we will develop practical synthesis of (-)-sabina ketone and enantioselective alkylation of conjugated sulfone. Menaquinol-7(MK-7) is a derivative of Vitamin K. MK-7 has been used as a food additives that is known to be good for osteoporosis and cardiovascular disease. There is no effective chemical synthesis yet. Scalable synthesis of MK-7 would provide efficient production of the valuable food additive as well as interesting synthetic pathway for polyprenyl alcohol.